Such release ski bindings are described in German Patent No. 2 533 337. In these conventional ski bindings the spring of the holding mechanism acts through a piston onto an approximately mushroom-shaped follower member, which is supported swingably to all sides in the housing of the holding mechanism. The stem portion of the mushroom-shaped follower member is received in a recess of a ski-fixed fitting. The ski shoe is, in these conventional ski bindings, held at its tip or toe by means of a rigid bar on the sole plate. The bar, however, prevents during a twisting fall the release of the ski shoe to a certain degree.
This disadvantage is avoided in the ski binding according to German Patent No. 2 324 078, however, this ski binding is very complicated in its design. In addition, in this ski binding the adjusting of the release moment is accomplished by two check nuts housed inside of the binding housing and, therefore, are accessible only after removing the housinglike front jaw from the ski. Therefore, the adjusting task can be accomplished only with difficulties.
The goal of the invention is to overcome the mentioned disadvantages of the conventional designs and to provide a release ski binding of the above-mentioned type, which is simple in its design and which can be adjusted easily externally of the ski binding to the desired release moment.
This goal is inventively attained primarily by providing a resilient holding mechanism being in the form of a U-shaped spring member having a bearing arranged in the region whereat the legs of the U are joined together. The spring member is securable as well as being adjustable in the longitudinal direction of the ski and with respect to the locking mechanism. The slide member is located between the legs of the spring member and is fastened to the sole plate at its upper end. Of course, the adjustment of the bearing could also occur against the action of a spring through a wedge or the like adjustable in the transverse direction of the ski as for example by a screw. However, it has been proven to be particularly advantageous to construct the bearing as a pin arranged on a travelling nut arranged on a screw which extends in the longitudinal direction of the ski. This enables it to be possible to adjust the desired release moment particularly sensitively.
Furthermore, the invention provides for the spring member to be arranged within a housing. The screw has at its end remote from the nut a part which is rotatably supported in a narrow sidewall of the housing, however, is secured against axial movement. The housing is secured below the sole plate on the ski. This measure ensures, on the one hand, a protected housing and an external accessibility of the screw located inside the housing and, on the other hand, preventing an undesired rotating of the screw under the influence of external forces. The further inventive characteristics lead also in this direction, namely, that for supporting the screw in the narrow sidewall of the housing the screw is provided with a flange and with a groove, whereby a snap ring is received in the groove, or that the screw is provided on its end projecting from the housing with a noncircular end, to facilitate engagement with a tool, such as a wrench.
In order to assure a reliable support of the spring member in all operating positions, it is inventively provided that the spring member is supported in the area of the free ends of its legs on a cross brace which extends transversely with respect to the longitudinal direction of the ski and parallel with respect to the upper surface of the ski, or that the spring member is centered in the skiing position of the ski binding relative to the vertical longitudinal center plane of the ski by a stop secured to the housing and extending between the ends of the two legs.
Actually it would by all means be possible to provide an enlarged head on the sliding member with semispherical projections, which engage correspondingly formed recesses in the legs of the spring member. However, it has proven to be particularly advantageous, if according to a further development of the invention the head of the sliding member has two upwardly converging surfaces with which are associated correspondingly formed surfaces on the underside of the two legs of the spring member.
In order to couple the spring member with the locking mechanism for the ski shoe, two plate-shaped control members for the control mechanism are arranged between the underside of the sole plate and the upper side of the housing, which control members are constructed as two-arm levers and are pivotal about a pin which is secured on the upper side of the housing and are coupled with the two legs of the spring member. Actually it would be possible to equip the control members with downwardly projecting pins extending through slotted holes in the upper side of the housing and being received in slotted holes, which extend in the transverse direction of the ski, in the two legs of the spring member. However, it has been proven as being particularly advantageous for the control members to have downwardly extending bent sections in the region of their arms adjacent the legs of the spring member, which bent sections extend through arc-shaped recesses in the upper side of the housing and rest on the outwardly facing sides of the two legs of the spring member. It is thereby preferable if the two control members are under the influence of a spring which urges the bent sections on the legs of the spring member together.
In order to assure a synchronous movement in opposite directions of the two control members during twisting falls, the invention includes the provision of link members hingedly connected to the arms of the control members having the bent sections thereon, which link members are connected by a pin guided in a slotted hole in the upper side of the housing and in a slot in a shoulder on the housing.
In order to hold the ski shoe on the sole plate, two pairs of bearing blocks are arranged on the end of the sole plate closest to the tip of the ski, on which bearing blocks are secured axles on which are supported angular or two-arm clamping jaws with slotted holes therein. According to another characteristic of the invention, a control plate is guided in the vertical direction for movement between each pair of bearing blocks, which control plate has in its lower half a groove which opens toward the vertical longitudinal center plane of the ski and which is approximately trapezoidal in cross section. At least one projection is arranged on each control member, which projection extends into the groove in the skiing position of the ski binding. This characteristic of the invention contributes to a reliable locking of the clamping jaws in the skiing position. A further characteristic of the invention leads also in this direction, namely, that each clamping jaw has two recesses in the lower lever arm which lies opposite the clamping arm, of which recesses the one serves, in the skiing position of the ski binding, to receive a projection of the sole plate and the other one for receiving the upper end of the control plate. It is thereby preferable if each control plate is under the influence of a spring which urges it upwardly or if each clamping jaw has an outer surface which extends approximately parallel with respect to the longitudinal axis of the slotted hole, which outer surface serves as bearing surface for the upper end of the associated control plate in the stepping-in position of the ski binding.
Of course it would be possible to bring about the opening of the ski binding by a cam disk pivotal about an axis which is vertical on the upper side of the ski and which during manual rotation spreads apart the two control members. However, it has been proven as being preferable to provide an enlargement through which extends a bolt in the transverse direction of the ski, and to provide an axle arranged on the shoulder in a bearing block, on which axle is supported a two-arm release lever having a lower, U-shaped constructed arm resting on the ends of the bolt. This construction permits an opening of the ski binding by means of the ski pole, whereby the force which is needed for the opening is kept within the usual limits.
Finally it is preferable for the head of the sliding member to have on both sides thereof a groove which is wedge-shaped in cross section, into which, in the skiing position, is received a correspondingly formed leg of the spring member, which is approximately trapezoidal in cross section. This measure permits an opening of the ski binding during a backward fall of the skier.